The ETS Transcription Factor ERF Controls the Exit from the Embryonic Rosette-stage of Pluripotency [RNAseq]

The naïve epiblast undergoes a transition to a pluripotent primed state during embryo implantation. Interestingly, a distinct intermediate stage during the naïve-to-primed transition has been recently described, the rosette stage. We propose the transcriptional repressor ERF as the MAPK-dependent switch that controls the exit from the rosette-stage of pluripotency. By using inducible ESC to genetically eliminate all RAS proteins, we show that, while differentiated RasKO ESC are reminiscent of the pluripotent rosette-stage, the absence of ERF overcomes the developmental blockage of RAS-deficient cells from this intermediate state. RNAseq data revealed that deletion of ERF restored the overall gene expression profile to a wild-type level in differentiated RasKO ESC. Mechanistically, ERF ensures naïve pluripotency by strengthening naïve pluripotent transcription factor binding and accessibility at specific ESC enhancers. Moreover, ERF regulates negatively the expression of the DNMT3 de novo methylases, which are essential for the extinction of the naïve transcriptional program. Our data revealed an essential role for ERF in the exit from rosette pluripotency as a regulator of the progression to primed pluripotency. RNAseq of untreated and OHT-treated Raslox/lox, ERFKO, RasKO, and RasKO; ERFKO ESC cultured in naïve conditions (2iL) or induced to differentiate to EpiLSC (FA) for 48 hours.